In this work, we extend the numerical micromagnetic approach to include the effects of microstructural pore-type defects and of a particle-size distribution function. Defects in nanoparticles (e.g., surface anisotropy, vacancies, antiphase boundaries) are known for a long time to give rise to spin disorder and in this way influence the macroscopic magnetic properties (see, e.g., Refs. [1]}, [2]}, [3]}, [4]}, [5]}). Therefore, finding their signature in the magnetic SANS cross section and correlation function is highly desirable.
